Solid composite propellant with autocondensation product of triaminoguanidinium azide as binder

ABSTRACT

Propellants in which particulated solid oxidizer and metallic fuel are combined with a binder low in carbon and rich in nitrogen are disclosed. The binders are autocondensation products of triaminoguanidinium azide. An additional organic high nitrogen gas producing compound may be included.

United States Patent Plomer et al.

[ Oct. 29, 1974 SOLID COMPOSITE PROPELLANT WITH AUTOCONDENSATION PRODUCT OF TRIAMINOGUANIDINIUM AZIDE AS BINDER Inventors: John J. Plomer; Harold E. Filter;

George A. Lane, all of Midland,

Mich. V H 7 M7 Assignee: The Dow Chemical Company,

Midland, Mich.

'Filed: Oct. 19, 1966 Appl. No.: 589,183

US. Cl l49/l9.l, 149/20, 149/36,

149/38, 149/42, 149/43 Int. Cl C06d 5/06 Field of Search 149/18, 109, 19, 20, 36,

[56] References Cited UNITED STATES PATENTS 2,992,908 7/1961 Hedrick et al. l49/l9.l X 2,995,432 8/1961 Corley et al. l49/l9.l X 3,375,230 3/1968 Oja et al. 149/19.1 x

Primary Examiner-Benjamin R. Padgett Attorney, Agent, or Firm-C. Kenneth Bjork [5 7] ABSTRACT 4 Claims, No Drawings This invention relates to propellants and more particularly is concerned with a novel solid propellant composition exhibiting a high specific impulse.

Conventional solid propellants based on carbon-rich binders, e.g., polyurethane, polybutadiene-acrylic acid,

2 prepared by pyrolyzing triaminoguanidinium azide or mixtures of from about 80 to about 98 parts by weight triaminoguanidinium azide and from about 2 to about 20 parts by weight malononitrile or cyanamide.

Fuels found to be suitable for use in the present composition include, for example, light metals such as magngsjur n aluminun beryllium, light metal hydrides such as aluminum hydride, magnesium hydride, lithium aluminum hydride and the like. Aluminum, beryllium, the

nitro-plasticized nitrocellulose and the like, suffer from l hydrides of these metals and mixtures thereof are P the disadvantage that extra oxidizer must be included ferred e to oxidize the carbon. Additionally, such propellants The Oxtchzer employed the composition usually are limited in performance by the equilibria between vSeleeted from t group Consisting. of ammonium P carbon, hydrogen, and oxygen containing compounds chlorate (hereln designated as AP), ammonium nitrate, in the combustion r d t 15 (designated as AN), hydrazine nitroformate (desiglt is a principal object of the present invention, therenailed as nitfonium Perchlorate gn as fore, to provide a novel solid propellant having a binder cyclotrimethylene-trinitramine, eyelotetrame' low in carbon and rich in nitrogen which avoids these thylehetetl'anltfamine and miXtures thereof- Ammoproblems associated with conventional binders as well Ilium Perchlorate flilronium Perchlorate, hy r zine nias provides a c iti hibiti a hi h energy troforrnate and mixtures thereof have been found to be tent. particularly effective oxidizers for use in the formula- This and other objects and advantages readily will beq f h high energy compositions. For optimum in come apparent from the detailed description presented mlX compatibility and storageabthty when hltl'ohlum hereinaft r perchlorate is used ordinarily a hard, fairly non-porous The present invention comprises a solid propellant Polymeric h Coating is applied to the hltrohium composition containing as a binder from about 5 to peltehlorate an amount of front ab0t1t5 to about 12 about 60 weight per cent of the autocondensation welght P Cent based on the hltrohlum Perchlorate product of triaminoquanidinium azide [hereinafter re- Welghtferred to as Polytaz], the autocondensation products of The l Sohd eompohehts as h the P e triaminoquanidinium azide modified with from about 2 formulations are l y In a finely l a P to about 20 weight per cent, based on the weight of late forth as eohvehtlohahy employed sohd P p triaminoguanidinium azide, of malononitrile [this conlaht gralhsdensation product hereinafter being referred to as Th Present Ph p ly e fabrleeted y Malonitaz] or cyanamide[this product being referred hhxlhg and hlehdthg the fuel, exldller and hlhdef to to herein as Cyanitaz] and mixtures thereof, from 'provlde a substantlally homogeneous blend. The forabout 3 to about 5 weight per cent of a particulated mulatlon is cast, extruded or otherwise formed and solid fuel and, balance, a particulated solid oxidizer. cured to protiuce a elestomet'le propellant gram Additionally, organic high nitrogen gas-producers such of predetermined eohfigutehehas triaminoguanidinium azide Satlsfactory propellant grams are produced by 1111K- triaminoguanidinium hydrazinium diazide (THAL 40 mg and bl endlng at a temperature of from about 30 to diaminoguanidinium azide, aminoguanidinium azide, ahout h e the thermeplastlc g hltt'ogeh hydrazinium azide hydrazinate hydrazinium azide binder ls m the llquld state, castlng and curlng at room monium azide and the like up to about 25 weight per temperature. Alternatlvely, the components can be cent of the composition weight optionally can be inmmed blended and Shaped or formed under preselure cluded in the composition. Triaminoguanidinium azide Fat .room tempereture thereby to fi a substamlmy has been found to be particularly suitable. vold f efi Ordinarily the composition comprises from about 15 The onowmg es serve to h to about 40 weight per cent of the high nitrogen mam trate the present lnventlon but are not meant to llmlt rial binder, from about 8 to about 30 weight per cent lli e fi v, W ,7 of a particulated solid fuel and from about 30 to about 77 weight per cent of particulated solid oxidizer, with EXAMPLE 1 or without from about 5 to about 20 weight per cent of A number of propellant grains were formed by blenda gas producing additive. ing finely divided solid fuel, oxidizer and lfolytaz. Each The Polytaz binders usually have 8 WC gram m mv of the blends was cast into a propellant gram, cured and ratio of from about 2.5/1 to about 3.3/1. The m l n nifired in a closed bomb. The heat energy liberated and trile modified products (Mal ni fll) ordinarily have a actual specific impulse were determined for each grain. N/C gram atom ratio of about 3. The cyanamide modi- The efficiency of each grain was determined by comfled materials (Cyanitaz) have a NIC gram atom ratio paring the observed specific Impulse wlth that theoretlof about 5. cally calculated for the composltlon. Table l, whlch fol- Conveniemly these c den ion Produ r lolyt umt iei l sdet ifllefll t 5t Table I Combustion Results Propcllant Composition AH lsp (obs.) Illp (then) Eff. Run No. Polytuz Al Bc AIH AP" NP (cut/g) tsec.) (see) ("/i.

l :5 l7 1% by flight, M35220 226 273.5 82.7

(incomplete Table l Continu e d Combustion Results Propellanl Composition AH,, lsp lobs.) lsp (then) Eff. ltun Nu Polytaz Al Be All-l, AP" NP (caljg) (see) (sec.) (H

" combustion of Al) 2 30 24 46 l607t7 266 288.5 92.3 3 25 30 45 2129179 286 299.9 95.2 4 l 48 42 2067144 284 304 93.5

'Ammonium perchlorate 'Nitronium perchlorate 7 EXAMPLE 2 EXAMPLE 4 Propellant grains were prepared by blending, casting and curing mixtures of Polytaz, aluminum hydride and ammonium perchlorate. In this preparation the binder and oxidizer were first mixed and the fuel component then blended into the composition. The grains were used as propellant in 50 gram end-burning motors. Smooth burning of the grain to completion was realized.

Composition data and motor firing results are summarized in Table ll.

A number of propellant motor grains and strands were prepared based on Polytaz. aluminum hydride and nitronium perchlorate, ammonium perchlorate or nitronium perchlorate-ammonium perchlorate mixtures. in these studies, the nitronium perchlorate used was coated with from about to about per cent of a proprietary polymeric composition.

The motor grains and strands were fabricated by first chilling the Polytaz binder whereupon it became brittle. The chilled binder and finely divided fuel compo- Table [1 Composition Motor Firing Results lsp, sec. Pa C* Burning Rate Run No. Polytaz AlH NH ClO, lcalc.) psi ft/sec. in/sec.

(weight percent) 4 40 I8 42 Z8l 673 4947 L69 C is the characteristic exhaust velocity V H EXAMPLE 3 nents were blended in a Waring Blender to provide a homogeneous, free-flowing mix having a coating of the To evaluate the properties of the high nitrogen bind- 40 alummum hydl'lde fuel the sheared P y P ers, the tensile properties of standard tensile test specimen prepared by compressing 50/50 weight per cent mixtures of Polytaz or Malonitaz with aluminum hydride were determined using an lnstron tester at a cross-head speed of 2 inches/minute. The hardness was determined using a Shore Durometer tester. Additionally. a simulated propellant grain was fabricated by the same technique wherein small glass beads were incorporated into the mix to simulate particulate nitronium perchlorate oxidizer. Table lll summarizes the physical properties obtained in these studies.

cles. Nitronium perchlorate was added and the resulting mixture blended. After blending, the composition was poured into a motor case or strand mold where it was pressurized to from about 100 to about 200 pounds per square inch, warmed to about 30 C. and then subjected to a low pressure. The resulting cured grains or strands were substantially void free.

Bomb combustion data were carried out on a number of compositions to determine the heat of explosion. The data and results from this test are summarized in Table IV.

Table III Max. Tensile Elon ation Strength at yie max. Durometer Run No. Composition (psi) (Hardness A) l Pol taz AIH l9 8 16 85 2 Ma onituz AlH 240 3 16 97 3 Malonitaz AIH, 308 8 22 96 simulated oxidizer Table IV Corn sition fiitromum Ammonium AH Run. No Polytaz AIH; Perchlorate Perchlorate (cal/gram) (weight per cent) l 30 45 1529 2 20 3O 5O i835 3 20 5 I943 A pressed strand of the composition employed in All motors burned smoothly with stable, normal Run 2 was tested to determine the burning rate. This burning being obtained at all test pressures. system gave a burning rate of 1.2 inches/second at 1000 psi with a pressure exponent of 0.45.

Thirty gram end-burning motors were prepared and 5 EXAM 5 tested at various pressures from about 50 to about 750 psia. The compositions employed in these runs are summarized in Table V.

A number of formulations of the present invention provldehigh energy propellants fabricated into propellant grains. The combustion temperature and theoreti- Table V l cal impulse of a number of such propellants were calcu- Comp' 9 r 4 in r'e'diehis h 7 lated. The propellant formulation data and perform- MHz NHCIO NOCIO Np ance results from this study are presented in Table V1 which follows.

Table V] Propellant Composition Results Run Comb. Temp. Specific lmp. No. Polytaz Malonitaz A1 Be AIH; BeH AP NP HNF TAZ K lsp. (sec) 1 36 54 4250 291.8 2 10 45 45 3905 297.3 3 30 55 4238 296.1 4 I5 39 46 3981 301.1 5 30 50 4099 300.5 6 20 36 44 3901 301.5 7 24 51 4062 296.2 8 25 45 3943 302.3 9 25 36 39 3599 292.6 10 30 24 46 3936 300.5 11 30 27 43 3852 301.7 12 30 30 40 3722 300.2 13 27 38 3619 298.4 14 35 24 4| 3756 300.4 15 35 21 44 3840 299.2- 16 24 36 3505 296.4 17 40 18 42 3731 296.9 18 15 30 55 3297 297.1 19 15 22 63 3531 298.4 20 20 27 53 3230 295.8 21 20 18 62 3438 293.9 22 15 35 50 3330 293.8 23 15 28 57 3487 291.3 24 20 30 50 3440 292.6 25 20 25 55 3398 290.4 26 30 27 43 3025 285.8 27 30 21 49 3172 286.0 28 40 I8 42 2893 278.9 29 20 30 50 3858 262.7 30 20 I5 65 3679 265.9 31 30 28 42 3448 265.8 32 30 I9 51 3601 274.0 33 30 I3 57 3490 272.5 34 35 17 48 3443 275 7 15 40 12 48 3218 270 6 36 40 9 51 3146 266 6 37 40 18 42 3276 274 8 38 17 38 3060 269.0 39 30 29 41 4174 268.9 40 30 23 47 4256 273.6 41 30 17 53 4163 272.7 42 30 23 47 3316 274 5 43 30 17 53 285.6 44 30 11 59 3465 281.5 45 I3 21 64 3974 280.5 46 15 15 70 4003 281.0 47 20 20 60 3802 281.9 48 20 14 66 3907 284.1 49 25 12 63 3769 286.0 50 25 18 57 3710 285.4 51 30 19 51 3506 280.8 52 30 13 57 3712 290.7 53 30 7 63 3495 281.8 54 35 12 53 3587 292.6 55 40 13 47 3318 289.2 56 40 7 53 3304 283.3 57 45 9 46 3277 289.3 58 30 22 48 3932 279.4 59 30 16 54 4461 289.9 60 30 13 57 4370 286 8 61 30 10 60 4188 282 0 62 40 16 44 3862 290 l 63 40 13 47 4120 296 3 64 40 I0 50 4081 293 6 65 50 10 40 3750 299 l 66 50 13 37 3502 290 1 67 50 7 43 3744 296 0 68 60 7 33 3309 291 9 69 60 4 36 3197 283.5 7 69. I0 30 3. .82 v23 -1 Table Vl:( IQntinued Prov QEQIKS R Comb. Temp. Specific Imp. No. Polytaz Malonitaz Al Be AIH; Bel-l AP NP HNF TAZ "K Isp, (sec 71 30 I6 54 3447 288.2 72 30 60 3599 299.6 73 30 7 63 3489 293.11 74 30 4 66 3354 285.1 75 16 64 3706 295.1 76 20 10 70 3777 296.7 77 4o 7 53 3280 291.11 78 40 13 47 3248 2117.4 79 I8 11.4 50.6 20 3553 294.1 80 23 10.5 46.5 20 3417 294.1 81 11 1 411.9 10 3477 293.11 82 11 47.5 3417 293.0 83 20 17 63 3441 312.6 84 2o 23 57 3214 319.5 85 20 29 51 2823 327.2 86 2o 32 48 3004 318.4 87 30 19 51 3136 313.1 88 30 25 45 2820 319.5 89 30 28 42 2845 310.7 90 20 22 58 3972 322.3 91 20 31 49 3239 328.4 92 20 34 46 3369 324.5 93 30 25 45 3390 323.11 94 30 31 39 2759 336.7 95 30 34 36 3139 316.6 96 20 15 65 3414 318.8 97 20 21 59 3209 319.1 98 30 14 56 3171 313.5 99 30 20 50 3012 310.6 100 25 14.3 40.7 20 3940 286.9 101 30 13 37 20 3765 286.5 102 35 14.3 40.7 10 3924 286.3 103 40 13 37 10 3740 285.8 104 45 12.4 32.6 10 3506 283.2 105 35 11 44 10 3896 297.0 106 40 10 40 10 3727 298.2 107 45 36 10 3538 2971 I08 30 3 12 55 3081 299.5 109 30 5 20 45 2887 309.7 110 30 6 24 40 2823 307.3 111 40 2 8 50 2850 285.9 112 40 5 20 35 2749 299.8 113 10 36 54 4232 2911.1 114 10 45 45 31169 296.4 115 15 33 52 4151 2911.8 116 15 42 43 3753 294.6 1 17 20 30 50 4048 298.2 118 20 36 44 3819 297.6 119 20 39 41 3619 291.5 120 25 27 48 3953 297.9 121 25 30 45 3851 298.3 122 25 33 42 3698 295.4 123 30 24 46 3844 296.3 124 30 27 43 3735 296.4 125 30 30 40 3561 292.3 126 10 30 50 10 4118 300.2 127 10 33 52 5 4195 299.6 128 10 42 43 5 3837 2911.0 129 10 39 41 10 3765 298.2 130 10 33 52 5 4174 299.6 131 10 39 46 5 3959 300.0 132 10 42 43 5 3799 296.8 133 10 30 50 10 4091 299.8 134 10 36 44 10 3892 300.8 135 10 27 48 15 4020 300.3 136 10 33 42 15 3821 301.2 137 10 24 46 20 3944 300.3 138 10 30 40 20 3745 300.9 139 10 33 37 20 3558 295.5

In a manner similar to that descnbed for the preceda. from about 5 to about 60 per cent of a binder 1ng Examples, sohd propellant composmons can be formember selected from the group consisting of the mulated usmg particulate fuels and oxidizers, gas proautocondensation product of tr1aminoguan1din1um ducing add1t1ves, and binder components Set forth azide, the autocondensation product herem. These can be used in various combinations triammoguamdmium az1de modified with from within the d1sclosed ranges. about 2 to about 20 we1ght per cent malononitrile,

Various mod1ficat1ons can be made in the present mthe autocondensation product vention w1thout departing from the spirit or scope tr1am1noguan1d1n1um az1de mod1fied w1th from thereof for 1t 1s understood that we l1m1t ourselves only about 2 to about 20 we1ght per cent cyanam1de and as defined 1n the appended claims. 65 mlX h r We claim:

I. A solid propellant composition comprising on a weight basis b. from about 3 to about 65 weight per cent of a particulated solid fuel, and

10 chlorate, hydrazine nitroformate and mixtures thereof.

3. The composition as defined in claim 1 and including, based on the total composition weight, up to about '25 per cent of an organic high nitrogen gas producing compound.

4. The composition as defined in claim 2 and including from about 5 to about 20 weight per cent triaminoguanidinium azide.

Po-wso UN TED STATES PATENT oTTTTT V QERTKFKCATE" 0F QQRREUNGN Patent No. 3,844,855 Dated October 29, 1974 v ni John J. Plomer, Harold E. Filter, George A. Lane It is certified that error appears in the above-idhtified patent and that said Letters Patent are hereby corrected as shown below:

Table VI, Run No. 43 and 44 should read as follows under the indicated headings Comb. Temp. Specific Imp.

Run No. NP I HNF TA'Z .K Isp. (sec.)

Signed and sealed this 18th day of February 1975.

(SEAL) Attest:

C. MARSHALL DANN RUTH C. MASON v Commissioner of Patents Attesting. Officer and Trademarks P051050 mam STATES WWW @FFEEE CETIHCTE o5 ERREQN Patent No. 3,844,855 Dated October 29, 1974 Inverftofls) John J" m r I Ear-Old E. Filter, George A, Lane It is certified that error appears in the above-ideratified patent and that sald Letters Patent are hereby corrected as shown below:

Table VI, Run No. 43 and 44 should read ae follows under 'the indicated headings 2 Run I (Zomba Temp. Specific Imp. No. NP I HNF 'I'A'Z .K 15p. (sec.)

Signed and sealed this 18th day of February 1975.

(SEAL) Attest:

' C. MARSHALL DANN RUTH C. MASON I Commissioner of Patents Attesting Officer and Trademarks: 

1. A SOLID PROPELLANT COMPOSITION COMPRISING ON A WEIGHT BASIS A. FROM ABOUT 5 TO ABOUT 60 PER CENT OF A BINDE MEMBER SELECTED FROM THE GROUP CONSISTING OF THE AUTOCONDENSATION PRODUCT OF TRIAMINOGUANIDINUM AZIDE, THE AUTOCONDENSATION PRODUCT OF TRIAMINOGUANIDINIUM AZIDE MODIFIED WITH FROM ABOUT 2 TO ABOUT 20 WEIGHT PER CENT MALONONITRILE, THE AUTOCONDENSATION PRODUCT OF TRIAMINOGUANIDINIUM AZIDE MODIFIED WITH FROM ABOUT 2 TO ABOUT 20 WEIGHT PER CENT CYANAMIDE AND MIXTURES THEREOF, B. FROM ABOUT 3 TO ABOUT 65 WEIGHT PER CENT OF A PARTICULATED SOILD FUEL, AND C. BALANCE A PARTICULATED SOLID OXIDIZER.
 2. The solid propellant composition as defined in claim 1 wherein on a weight basis the binder ranges from about 15 to about 40 per cent, the particulated solid fuel is from about 8 to about 30 per cent, said fuel being a member selected from the group consisting of aluminum, beryllium, aluminum hydride, beryllium hydride and mixtures thereof, and, the particulate solid oxidizer ranges from about 30 to about 77 per cent, said oxidizer being a member selected from the group consisting of ammonium perchlorate, nitronium perchlorate, hydrazine nitroformate and mixtures thereof.
 3. The composition as defined in claim 1 and including, based on the total composition weight, up to about 25 per cent of an organic high nitrogen gas producing compound.
 4. The composition as defined in claim 2 and including from about 5 to about 20 weight per cent triaminoguanidinium azide. 